Evidence that Bacillus subtilis sporulation induced by the stringent response is caused by the decrease in GTP or GDP.
Partial amino acid deprivation of Bacillus subtilis, which evokes the stringent response, initiates sporulation not because the highly phosphorylated guanine nucleotides guanosine-5'-diphosphate-3'-diphosphate (ppGpp) and guanosine-5'-triphosphate-3'-diphosphate (pppGpp) increase but because GTP decreases. This was shown with a mutant (Myc) partially resistant to mycophenolate, an inhibitor of IMP dehydrogenase. Upon amino acid deprivation, the Myc mutant (62032) showed the usual increase in ppGpp and pppGpp but a reduced decrease in GTP, and only few cells sporulated. Extensive sporulation was restored by the addition of mycophenolate or decoyinine, and inhibitor of GMP synthetase, which caused a further decrease in GTP.
D000596:Amino Acids / Q000378:metabolism; D001412:Bacillus subtilis / Q000235:genetics / Q000502:physiology*; D006150:Guanine Nucleotides / Q000378:metabolism*; D006153:Guanosine Diphosphate / Q000378:metabolism*; D006158:Guanosine Pentaphosphate / Q000378:metabolism; D006159:Guanosine Tetraphosphate / Q000378:metabolism; D006160:Guanosine Triphosphate / Q000378:metabolism*; D009154:Mutation; D009173:Mycophenolic Acid / Q000494:pharmacology; D013171:Spores, Bacterial / Q000502:physiology
D000596:Amino Acids; D006150:Guanine Nucleotides; D006153:Guanosine Diphosphate; D006159:Guanosine Tetraphosphate; D006158:Guanosine Pentaphosphate; D006160:Guanosine Triphosphate; D009173:Mycophenolic Acid